3,786 research outputs found

    Chronicle of a Pandemic Foretold. CEPS Policy Insights No 2020-05 / March 2020

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    In just a few weeks, COVID-19 appeared in China and quickly spread to the rest of the world, including Europe and the United States. Many have rushed to describe the outbreak as a ‘black swan’ – an unpredictable event with extremely severe consequences. However, COVID-19 was not only predictable ex post: it was amply predicted ex ante. This allows us to draw some preliminary lessons: • First, economic policy will need to shift from its current focus on efficiency, towards a greater emphasis on resilience and sustainability. • Second, a more centralised governance to address health emergencies is needed. • Third, Europe should create a centre for the prevention of large-scale risks. • Fourth, digital technologies, if handled with care, can be an important part of both a mitigation and a response strategy. • Fifth, Europe should improve its science advice and communication functions. Finally, there are many ways to pursue enhanced resilience and responsiveness, but not all of them are compatible with sustainability and democratic values. The challenge is to find an adequate policy mix, which safeguards individual rights and liberties, protects the economy, and at the same time strengthens government preparedness for cases of epidemics and pandemics

    Study of the interface reactions between two lead-free solders and copper substrates

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    Traditional Sn-Pb solder alloys are being replaced, because of environmental and health concerns about lead toxicity. Among some alternative alloy systems, the Sn-Zn and Sn- Cu base alloy systems have been studied and reveal promising properties. The reliability of a solder joint is affected by the solder/substrate interaction and type of layers formed at the interface. The solder/substrate reactions, for Sn-Zn and Sn-Cu base solder alloys, were evaluated in what concerns the morphology and chemical composition of the interface layer. The phases formed at the interface between the Cu substrate and a molten lead-free solder were studied, at 250 ºC, with different stage times and alloy compositions. The melting temperatures of the studied alloys, were determined by Differential Scanning Calorimetry (DSC). Identification of equilibrium phases, formed at the interface layer, and the evaluation of their chemical compositions were performed by Scanning Electron Microscopy (SEM/EDS). Results of the studied systems were compared with the interface characteristics obtained for a traditional Sn-Pb solder alloy. Different interface characteristics were obtained, namely for the alloys containing Zn

    Eficiência da adubação residual com rochas brasileiras para a cultura da soja.

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    O objetivo deste trabalho foi avaliar a eficiência agronômica residual de rochas como fertilizantes multinutrientes no desenvolvimento e no estado nutricional da soja cultivada em sucessão ao girassol. O experimento foi executado em casa-devegetação, em vasos contendo 3 kg dos solos com características distintas, um Latossolo Vermelho distroférrico (LVdf) e um Neossolo Quartzarênico (NQ). Os tratamentos foram dispostos no esquema fatorial (solos x fontes) e delineamento em blocos casualizados, com quatro repetições. Além de uma testemunha não adubada, testaram-se as fontes de potássio, arenito vulcânico, brecha alcalina, carbonatito, biotita xisto, ultramáfica alcalina e a fonte padrão de potássio, cloreto de potássio, aplicadas na dose de 150 mg kg-1 de K2O por ocasião da semeadura do girassol. Cultivaram-se duas plantas de soja BRS 232 por vaso, as quais foram coletadas no estádio de florescimento pleno para a avaliação da produção de matéria seca da parte aérea, além dos teores de macro e micronutrientes nos tecidos. As rochas ultramáfica alcalina e biotita xisto apresentaram os maiores índices de eficiência agronômica residual para a produção de matéria seca pela soja. As rochas diferem na capacidade de disponibilização de nutrientes às plantas em função da composição mineralógica e apresentam características de fertilizantes multinutrientes, o que deve ser considerado no cálculo de balanço da adubação

    Effect of the Bi content on the mechanical properties of a Sn-Zn-Al-Bi solder alloy

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    Because of environmental and health concerns, some alternative solder alloys, named lead-free ones, are being developed. Among them, the Sn-Zn-Al system has been studied and reveals promising properties. Selection of the solder alloys, for the electronic industry applications, is conditioned by their mechanical properties due to the stress produced in service. The studied alloys were produced by melting the pure elements in a resistance furnace, under inert atmosphere, and pouring in a steel mould. The samples were heat treated for homogenization of the microstructure. The produced alloys were analyzed by XRF spectrometry and Scanning Electronic Microscopy (SEM/EDS) for chemical and microstructural characterization. In this work the presence of bismuth, in the range of 0-7 weight %, was evaluated in what concerns to the as-cast and homogenized microstructures and mechanical properties. The mechanical properties of the produced alloys, in the as-cast and homogenized conditions, have been determined by tensile strength and hardness tests. The results obtained showed that bismuth has an important effect on the mechanical behavior of the alloys, namely, in the transition from ductile to brittle behavior. This behavior was correlated with the samples microstructures.(undefined

    Eficiência da adubação residual com rochas brasileiras para a cultura da soja.

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    RESUMO: O objetivo deste trabalho foi avaliar a eficiência agronômica residual de rochas como fertilizantes multinutrientes no desenvolvimento e no estado nutricional da soja cultivada em sucessão ao girassol. O experimento foi executado em casa-devegetação, em vasos contendo 3 kg dos solos com características distintas, um Latossolo Vermelho distroférrico (LVdf) e um Neossolo Quartzarênico (NQ). Os tratamentos foram dispostos no esquema fatorial (solos x fontes) e delineamento em blocos casualizados, com quatro repetições. Além de uma testemunha não adubada, testaram-se as fontes de potássio, arenito vulcânico, brecha alcalina, carbonatito, biotita xisto, ultramáfica alcalina e a fonte padrão de potássio, cloreto de potássio, aplicadas na dose de 150 mg kg-1 de K2O por ocasião da semeadura do girassol. Cultivaram-se duas plantas de soja BRS 232 por vaso, as quais foram coletadas no estádio de florescimento pleno para a avaliação da produção de matéria seca da parte aérea, além dos teores de macro e micronutrientes nos tecidos. As rochas ultramáfica alcalina e biotita xisto apresentaram os maiores índices de eficiência agronômica residual para a produção de matéria seca pela soja. As rochas diferem na capacidade de disponibilização de nutrientes às plantas em função dacomposição mineralógica e apresentam características de fertilizantes multinutrientes, o que deve ser considerado no cálculo de balanço da adubação. ABSTRACT: The aim of this work was to evaluate the residual efficiency of ground rocks as multi-nutrient fertilizers on the development and nutritional status of the soybean after sunflower, under greenhouse conditions. Treatments were displayed in a factorial scheme (2 soils x 6 potassium sources), in a completely randomized blocks design with four replications. Two soybean BRS 232 plants were grown in pots containing 3 kg of two soils, a Rhodic Hapludox and an Ustoxic Quartzipsamment. Besides a control treatment (without potassium), the sources, volcanic sandstone, alkaline breccia, carbonatite, biotite schist, alkaline ultramaphic, and potassium chloride, as the standard fertilizer source, were applied in a rate of 150 mg kg-1 of K2O, before the first crop sowing. At the full bloom stage, shoot dry matter yield and macro and micronutrients concentration in soybean tissues were evaluated. Alkaline ultramaphic and biotite schist rocks showed the highest residual agronomic efficiencies to dry matter yield of soybean. The rock sources presented differences in the capacity to supply nutrients for crops as a function of their mineralogical composition. The rocks act like multinutrient fertilizers and this characteristic must be considered in the fertilization progra

    Abuso de sustancias y percepción de la salud en niños y adolescentes españoles

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    [EN] Objective: The aim of this study was to analyze subs- tance abuse and health self-perception in children and adolescents from the province of Cádiz (Spain). Methodology: Participants were 738 students, 50.9 boys and 49.1% girls, from elementary school to high school (1 st to 12 th grade, mean age 12.2. years), who res- ponded a Spanish adaptation of the Health Behavior in School-aged Children Inventory. Results: No difference was observed in percentage of boys and girls reporting to smoke or drink alcohol. Smo- king and drinking habits increased with age, being higher in 11 th and 12 th grade students. Significant differences were observed among the percentage of smokers and non smokers recognizing to have parents, older brothers or friends who smoke. Rates of drug abuse were generally low, being cannabis the most frequently consumed illicit drug. Most respondents had a perception of excellent or good health, with no significant gender differences. About half of subjects considered that health exclusively depends on self behavior, but an important percentage also gave a relevant role to luck. Stomach-ache was the most frequent physical complaint, followed by headache. Psychological complaints mainly corresponded to ner- vousness and bad temper. Only a small percentage of sub- jects declared the use of medicines or tablets without prescription. No significant difference in the percentage of respondent who perceived an excellent or good health was observed among substance users and non users. Conclusions: Substance abuse and health self-percep- tion in children and adolescents are the result of the inte- raction of a complex series of individual and social fac- tors. Activities aimed to improve health focusing on partial aspects of adolescents’ lifestyle most probably will have limited results, and global programs are required.[ES] Objetivo: El objetivo del estudio ha sido analizar el uso de sustancias tóxicas y la autopercepción del estado de salud en niños y adolescentes de la provincia de Cádiz. Metodología: Participaron 738 alumnos, 50.9% de chi- cos y 49.1% de chicas, que cursaban educación primaria y secundaria (desde 1º educación primaria a 2º de bachi- llerato, edad media 12,2 años), a los que se aplicó la ver- sión española del Inventario de Conductas de Salud en Escolares. Resultados: No se observaron diferencias en el porcen- taje de chicos y chicas que fumaban o bebían alcohol. Los hábitos de consumo de tabaco y alcohol se incrementaban con la edad, alcanzando sus máximos valores en los alum- nos de bachillerato. Se encontraron diferencias significa- tivas en el porcentaje de fumadores y no fumadores que reconocían el tener padres, hermanos mayores o amigos que fumaban. El consumo de drogas ilegales era general- mente reducido, predominando la utilización del canna- bis. La mayoría de los sujetos tenían una percepción de su salud como excelente o buena. En torno a la mitad de los encuestados consideraban que la salud depende exclusi- vamente del propio comportamiento, aunque una parte importante también le otorgaba un papel relevante a la suerte. El dolor de estómago era el síntoma físico más fre- cuente, seguido del dolor de cabeza. Entre los síntomas psicológicos predominaban el nerviosismo y el estar irri- tado o enfadado. Solo un pequeño porcentaje declaraba consumir medicamentos o píldoras no prescritos. No se observaron diferencias significativas en el porcentaje de los que reconocían una salud excelente o buena entre los usuarios y no usuarios de sustancias tóxicas. Conclusiones: El abuso de sustancias tóxicas y la auto- percepción del estado de salud en niños y adolescentes es el resultado de la interacción de una compleja serie de facto- res individuales y sociales. Las actividades diseñadas para la mejora de la salud centradas en aspectos parciales del estilo de vida tendrán probablemente resultados limitados, requiriéndose el desarrollo de programas globales.S

    PillCam COLON 2© in Crohn's disease: A new concept of pan-enteric mucosal healing assessment

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    AIM To evaluate mucosal healing in patients with small bowel plus colonic Crohn's disease (CD) with a single non-invasive examination, by using PillCam COLON 2 (PCC2). METHODS Patients with non-stricturing nonpenetrating small bowel plus colonic CD in sustained corticosteroid-free remission were included. At diagnosis, patients had undergone ileocolonoscopy to identify active CD lesions, such as ulcers and erosions, and small bowel capsule endoscopy to assess the Lewis Score (LS). After = 1 year of follow-up, patients underwent entire gastrointestinal tract evaluation with PCC2. The primary endpoint was assessment of CD mucosal healing, defined as no active colonic CD lesions and LS < 135. RESULTS Twelve patients were included (7 male; mean age: 32 years), and mean follow-up was 38 mo. The majority of patients (83.3%) received immunosuppressive therapy. Three patients (25%) achieved mucosal healing in both the small bowel and the colon, while disease activity was limited to either the small bowel or the colon in 5 patients (42%). It was possible to observe the entire gastrointestinal tract in 10 of the 12 patients (83%) who underwent PCC2. CONCLUSION Only three patients in sustained corticosteroid-free clinical remission achieved mucosal healing in both the small bowel and the colon, highlighting the limitations of clinical assessment when stratifying disease activity, and the need for pan-enteric endoscopy to guide therapeutic modification

    The First Brown Dwarf Discovered by the Backyard Worlds: Planet 9 Citizen Science Project

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    The Wide-field Infrared Survey Explorer (WISE) is a powerful tool for finding nearby brown dwarfs and searching for new planets in the outer solar system, especially with the incorporation of NEOWISE and NEOWISE-Reactivation data. So far, searches for brown dwarfs in WISE data have yet to take advantage of the full depth of the WISE images. To efficiently search this unexplored space via visual inspection, we have launched a new citizen science project, called "Backyard Worlds: Planet 9," which asks volunteers to examine short animations composed of difference images constructed from time-resolved WISE coadds. We report the discovery of the first new substellar object found by this project, WISEA J110125.95+540052.8, a T5.5 brown dwarf located approximately 34 pc from the Sun with a total proper motion of \sim0.7 as yr1^{-1}. WISEA J110125.95+540052.8 has a WISE W2W2 magnitude of W2=15.37±0.09W2=15.37 \pm 0.09, this discovery demonstrates the ability of citizen scientists to identify moving objects via visual inspection that are 0.9 magnitudes fainter than the W2W2 single-exposure sensitivity, a threshold that has limited prior motion-based brown dwarf searches with WISE.Comment: 9 pages, 4 figures, 1 table. Accepted for publication in the Astrophysical Journal Letter

    Vertically aligned carbon nanotubes for microelectrode arrays applications

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    In this work a methodology to fabricate carbon nanotube based electrodes using plasma enhanced chemical vapour deposition has been explored and defined. The final integrated microelectrode based devices should present specific properties that make them suitable for microelectrode arrays applications. The methodology studied has been focused on the preparation of highly regular and dense vertically aligned carbon nanotube (VACNT) mat compatible with the standard lithography used for microelectrode arrays technology
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